Fuel fliter or what?

So I was tearing apart my 1974 dart special edition this afternoon and I saw something in the engine compartment that isnt in my 74 dart swinger and that Ive never seen before. Its a big black cylinder, has three hoses that go to it, on the cylinder it says under the three what they go to, which is, carb, fuel tank, and purge(not sure what this is), it is on the left side of the engine compartment (when looking at the engine) by the radiator. Can anyone explain to me what that is? Thanks

And ya I spelled filter wrong in the title, sorry.
Author: 74dart